Of the form:

```
warning: empty line after doc comment
   --> src/lib.rs:120:1
    |
120 | / /// ```
121 | |
    | |_^
...
124 |   pub enum PrivateKeyDer<'a> {
    |   -------------------------- the comment documents this enum
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#empty_line_after_doc_comments
    = note: `#[warn(clippy::empty_line_after_doc_comments)]` on by default
    = help: if the empty line is unintentional remove it
```

Of the form:

```
error: redundant pattern matching, consider using `is_none()`
   --> tests/pem.rs:312:13
    |
312 |     assert!(matches!(iter.next(), None));
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `iter.next().is_none()`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_pattern_matching
    = note: `-D clippy::redundant-pattern-matching` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::redundant_pattern_matching)]`

error: could not compile `rustls-pki-types` (test "pem") due to 1 previous error
```